We might ask, “Given my present situation, how long should I stay with uncomfortable feelings?”  This is a good question, yet there is no right answer. We simply get accustomed to coming back to the present just as it is for a second, for a minute, for an hour — whatever is currently natural — without its becoming an endurance trial. Just pausing for two to three breaths is a perfect way to stay present. This is a good use of our life. Indeed, it is an excellent, joyful use of our life.  

Pema Chodron, Taking the Leap.